As Charles grew old his command over Germany weakened. His opponents consolidated their position while he was distracted by wars with the French and the Turks. In 1526, at Speyer, in the Recess Declaration of the Diet, they managed to insert a clause for princely liberty in religion. In other words, they declared that the ruler has the right to determine the state’s religion. At the second Diet of Speyer in 1529, they formally lodged the Protest which gave them their name.

At Augsburg in 1530, they presented the Protestant manifesto,
composed by Melanchthon. Charles refused to acknowledge their protest.
He set April 1531 as the deadline for submitting to his dictum.
In defiance, the Protestant Princes formed the armed League of Schmalkalden.
From now on the Catholic-Protestant divide was clearly demarcated.
The provinces were free to select either Protestantism or Catholicism
and people were encouraged to emigrate accordingly.